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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* JZ4740 Watchdog driver
*
* Copyright (C) 2014 Antony Pavlov <antonynpavlov@gmail.com>
*
* Based on jz4740_wdt.c from linux-3.15.
*
* Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net>
*/
#include <common.h>
#include <init.h>
#include <restart.h>
#include <io.h>
#define JZ_REG_WDT_TIMER_DATA 0x0
#define JZ_REG_WDT_COUNTER_ENABLE 0x4
#define JZ_REG_WDT_TIMER_COUNTER 0x8
#define JZ_REG_WDT_TIMER_CONTROL 0xC
#define JZ_WDT_CLOCK_PCLK 0x1
#define JZ_WDT_CLOCK_RTC 0x2
#define JZ_WDT_CLOCK_EXT 0x4
#define JZ_WDT_CLOCK_DIV_SHIFT 3
#define JZ_WDT_CLOCK_DIV_1 (0 << JZ_WDT_CLOCK_DIV_SHIFT)
#define JZ_WDT_CLOCK_DIV_4 (1 << JZ_WDT_CLOCK_DIV_SHIFT)
#define JZ_WDT_CLOCK_DIV_16 (2 << JZ_WDT_CLOCK_DIV_SHIFT)
#define JZ_WDT_CLOCK_DIV_64 (3 << JZ_WDT_CLOCK_DIV_SHIFT)
#define JZ_WDT_CLOCK_DIV_256 (4 << JZ_WDT_CLOCK_DIV_SHIFT)
#define JZ_WDT_CLOCK_DIV_1024 (5 << JZ_WDT_CLOCK_DIV_SHIFT)
#define JZ_EXTAL 24000000
struct jz4740_wdt_drvdata {
struct restart_handler restart;
void __iomem *base;
};
static void __noreturn jz4740_reset_soc(struct restart_handler *rst)
{
struct jz4740_wdt_drvdata *priv =
container_of(rst, struct jz4740_wdt_drvdata, restart);
void __iomem *base = priv->base;
writew(JZ_WDT_CLOCK_DIV_4 | JZ_WDT_CLOCK_EXT,
base + JZ_REG_WDT_TIMER_CONTROL);
writew(0, base + JZ_REG_WDT_TIMER_COUNTER);
/* reset after 4ms */
writew(JZ_EXTAL / 1000, base + JZ_REG_WDT_TIMER_DATA);
/* start wdt */
writeb(0x1, base + JZ_REG_WDT_COUNTER_ENABLE);
mdelay(1000);
hang();
}
static int jz4740_wdt_probe(struct device *dev)
{
struct resource *iores;
struct jz4740_wdt_drvdata *priv;
priv = xzalloc(sizeof(struct jz4740_wdt_drvdata));
iores = dev_request_mem_resource(dev, 0);
if (IS_ERR(iores)) {
dev_err(dev, "could not get memory region\n");
return PTR_ERR(iores);
}
priv->base = IOMEM(iores->start);
dev->priv = priv;
priv->restart.name = "jz4740-wdt";
priv->restart.restart = jz4740_reset_soc;
restart_handler_register(&priv->restart);
return 0;
}
static __maybe_unused struct of_device_id jz4740_wdt_dt_ids[] = {
{
.compatible = "ingenic,jz4740-wdt",
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(of, jz4740_wdt_dt_ids);
static struct driver jz4740_wdt_driver = {
.name = "jz4740-wdt",
.probe = jz4740_wdt_probe,
.of_compatible = DRV_OF_COMPAT(jz4740_wdt_dt_ids),
};
device_platform_driver(jz4740_wdt_driver);
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